type of hat, 1897, from name of Trilby O'Ferrall, eponymous heroine of the novel by George du Maurier (1834-1896), published in 1894. In the stage version of the novel, the character wore this type of soft felt hat. In plural, also slang for "feet" (1895), in reference to the eroticism attached in the novel to the heroine's bare feet. Related: Trilbies.